(99m)Tc-pyrophosphate scintigraphy for differentiating light-chain cardiac amyloidosis from the transthyretin-related familial and senile cardiac amyloidoses.

Background: Differentiating immunoglobulin light-chain (AL) from transthyretin-related cardiac amyloidoses (ATTR) is imperative given implications for prognosis, therapy, and genetic counseling. We validated the discriminatory ability of (99m)Tc-pyrophosphate ((99m)Tc-PYP) scintigraphy in AL versus ATTR.

Methods And Results: Forty-five subjects (12 AL, 16 ATTR wild type, and 17 ATTR mutants) underwent (99m)Tc-PYP planar and single-photon positive emission computed tomography cardiac imaging.